The Price of Failure

The Path to 9/11: Lost Warnings and Fatal Errors

By the time the hijackers made their way into the U.S., memos, photographs, and intercepts had sounded alarms inside the C.I.A., White House, F.B.I., and European intelligence services. Could better cooperation have stopped the attacks? Ned Zeman, David Wise, David Rose, and Bryan Burrough show how the hideous “Planes Operation” took shape as the C.I.A.’s bin Laden point man, Mike Scheuer, counterterrorism czar Richard Clarke, the F.B.I.’s John MacGaffin, and others fought—yet couldn’t work together—to prevent it.

With his salt-and-pepper hair, white shirt, and sensible shoes, Mike Scheuer, 44, looked like a rumpled academician, or maybe a consultant for one of the many defense contractors [#image: /photos/54cbf62044a199085e88c698]sprinkled around the Washington Beltway.

In reality, his job was considerably more interesting. Starting in 1996, he was the man the C.I.A. had assigned to hunt down, capture, or kill Osama bin Laden.

Of all the agency’s far-flung stations—from Moscow to Prague to Beijing—Scheuer’s was unique. Known among the spooks as a “virtual station,” it was not overseas but near the C.I.A. headquarters, in Langley, Virginia, eight miles west of Washington. The station was the first to target an individual rather than a country.

This was not because bin Laden was perceived at the time to be the arch-enemy and mastermind of global terrorism that he is today. Back then, those few in government who even knew his name referred to him merely as “a terrorist financier.”

Still, “we had run across bin Laden in a lot of different places,” recalls Scheuer, “not personally but in terms of his influence, either through rhetoric, through audiotapes, through passports, through money—he seemed to turn up everywhere. So when we chose him [for the first virtual station], the first responsibility was to find out if he was a threat.”

Although officially called Bin Laden Issue Station, everyone who worked there called it “Alec Station,” after Scheuer’s son. Many at the agency questioned the efficacy of a C.I.A. Middle East station based in suburban Virginia. Not to mention that Alec Station was an interagency unit “tasked” by C.I.A. officers and F.B.I. agents. “If you were an up-and-coming C.I.A. officer,” says former C.I.A. case officer Robert Baer, “you didn’t want to get sent down there to sit around with those F.B.I. guys.”

Alec Station was so low-profile it was housed “off campus,” in nearby Tysons Corner, behind an unmarked door in a nondescript office building filled with defense contractors. (Eventually, it was moved to the C.I.A.’s Counterterrorist Center, or CTC, in Langley.) There, every morning, Scheuer and his staff of 15 or so—mostly junior-grade, mostly female—toiled in their cubicles. They soon discovered that bin Laden “was much more of a threat than I had thought,” recalls Scheuer. “It became very clear very early that he was after, for example, W.M.D., and we showed conclusively at that point that he didn’t have them. But we had never seen as professional an organization in charge of procurement.”

By 1998, Scheuer and his staff had become so passionate about going after bin Laden that he felt his superiors weren’t getting it. Scheuer later informed Congress that when Alec Station had obtained detailed intelligence in 1996 about attempts by bin Laden to acquire nuclear weapons, the higher-ups decided to suppress the information. Only after three officers “of the agency’s bin Laden cadre” complained and forced an internal review was the information released more fully to analysts, policymakers, and community leaders.

A bunker mentality set in at Alec Station. Them against us. Up on Langley’s seventh floor, in the executive suites, the top brass started to view Scheuer as a hysteric, spinning doomsday scenarios, a sort of Kurtz-like figure. “The Manson family,” some started calling him and his staff. “The overwhelming majority of officers who worked for me were women,” Scheuer recalls. “And they don’t care for that. They don’t care for women, period, but they especially don’t care for successful women.”

Yet even some of Scheuer’s supporters admit that he had become difficult. “He’s a good guy, [but] he’s an angry guy,” says John MacGaffin, a former top C.I.A. official for clandestine operations and later a senior adviser to the F.B.I.

Strangely, Richard Clarke, the White House counterterrorism czar, and Scheuer did not get along. “Strangely” because they were among the few officials in government who shared a bin Laden obsession before 9/11. Scheuer and Clarke were, in many ways, doppelgängers: brainy, workaholic, cranky, impolitic, stubborn. Like Scheuer, Clarke had an intensely loyal staff, and he often ruffled feathers with his abrasiveness and impatience. A former C.I.A. insider says, “I can say that, among individuals that I tend to trust, Clarke was regarded as more serious about terrorism in the 1990s than just about anybody else in the U.S. government, but he was a truly painful individual to work with.”

That’s exactly how Clarke views Scheuer. “Throwing tantrums and everything doesn’t help,” says Clarke. “Fine that you came to the same conclusion that we all came to, fine that you’re all worked up about it, and you’re having difficulty getting your agency, the rest of your agency, to fall in line, but not fine that you’re so dysfunctional within your agency that you’re making it harder to get something done.”

For his part, Scheuer recalls that “Mr. Clarke was an interferer of the first level, in terms of talking about things that he knew nothing about and killing them.” He adds, “Mr. Clarke was an empire builder. He built the community, and it was his little toy. He was always playing the F.B.I. off against us or us against the N.S.A. [National Security Agency].”

Such a relationship did not bode well for early efforts to target bin Laden. But there was worse: Scheuer and the F.B.I. agents assigned to his office didn’t get along, either.

From the start, key F.B.I. officials resisted the idea of cooperating with Alec Station. Chief among them was the F.B.I.’s top counterterrorism guy, a swaggering, old-school G-man named John O’Neill (who died on 9/11 in the World Trade Center, where he had just begun a new job as chief of security). “O’Neill just fought it and fought it [cooperating with Alec Station],” MacGaffin recalls, and O’Neill and Scheuer “were at each other’s throats.”

Very early on O’Neill refused to hand over to the C.I.A. a notebook taken from an al-Qaeda operative captured by the F.B.I. According to MacGaffin, O’Neill said, “Fuck you. I’ve got it. I’m keeping it. It’s mine. This is the F.B.I.’s.” Technically, the notebook was evidence in a court case, but MacGaffin, who was by this time at the F.B.I., recalls that “O’Neill said to me personally, ‘I just don’t want them to have it. I want the F.B.I. to control this.… ’ They [the F.B.I.] kept it for like 12 months, and what that means is that all the C.I.A.’s years of analytic experience and information in databases on these very terrorist organizations were not brought to bear on that book for a very long time.”

On another occasion an F.B.I. agent at Alec Station was caught stuffing C.I.A. files down his shirt to take back up to O’Neill in New York. “So here Scheuer’s getting angry, knows he’s being had,” recalls MacGaffin.

According to Scheuer, the F.B.I. did little to follow up on the intelligence from Alec Station. In his 2004 book, Imperial Hubris, which the C.I.A. required him to publish anonymously, Scheuer wrote, “The FBI officers I worked with—some of whom I managed—were ordered by their superiors to stay side-by-side with my agency.… Only one of these FBI officers … did his best to run down U.S.-based al Qaeda leads provided by my service.”

Nor, Scheuer says, did the F.B.I. offer much help. In his interview with V.F., he adds, “I bet we sent 700 or 800 requests for information to the F.B.I., and we never got an answer to any of them.”

Could the 9/11 attacks have been prevented if the people in charge of protecting us had cooperated better? Even at 567 densely worded, sometimes electrifying pages, the published report of the 9/11 commission studiously avoids answering that question. Into that vacuum, some are already coming forward to argue that the attacks were not, in fact, preventable.

Perhaps unsurprisingly, the most persuasive of the apologists reside at the senior levels of the F.B.I. and the C.I.A. “We could have gone to [hijacking leader] Mohammed Atta’s door on September 10 and he’d go, ‘Hi, Mr. F.B.I., I’m Mohammed Atta. I’m going to flight school—come on in,’” says Michael Rolince, a special agent in charge of counterintelligence for the F.B.I.’s Washington field office. “‘What are you doing at flight school?’ we ask. [He says,] ‘My sole ambition is to be an EgyptAir pilot. How else can I help you?’ And the F.B.I.’s second question is … what? Not a single agency in the world wants this guy. There wouldn’t be a thing we could do. You think one of those guys would’ve broken [and talked] like Joe Bag O’Donuts in Boston? No. These guys were pros. For us to have done anything, these guys had to make a mistake. And they didn’t. Could we have generated enough information—ever—to keep them off those planes? I doubt it.”

Mary Galligan, who headed the F.B.I.’s domestic-terror squad in the summer of 2001, voices a similar view: “If I had Atta—say, we got a call from a next-door neighbor, and we sent a guy out there—he’s not gonna give us the plan, so the agent is gonna come back to me and say, ‘Mary, he’s nothing.’ And what could I do? Nothing. Or let’s assume we learned the hijackers’ names in 2000. We would have surveilled them and listened to their conversations. But we know now they didn’t even know the plan at that time. If we approached them, they would have left the country. Would bin Laden then have sent more people? Yes.”

During the 9/11-commission hearings, Director of Central Intelligence (D.C.I.) George Tenet was asked, “Do you think if you had gotten in any way, shape, or form bin Laden in the year 2001 you would have prevented the 9/11 attacks?” Tenet replied, “I don’t believe so.”

In the end, many of these officials circle back to the same point. They argue that the failure to prevent the attacks wasn’t a “failure of imagination,” as the 9/11 commission famously called it. It was a failure of resources, they insist. The intelligence professionals maintain that America’s intelligence apparatus simply didn’t have the people, the money, the mandate—or the right laws in place—to stop the attacks.

But others, such as Scheuer, see 9/11, more than anything, as a failure of the intelligence bureaucracy, caused by a lack of cooperation among its components. On a half-dozen occasions, the future hijackers popped up on intelligence radar screens. In most cases, they weren’t properly investigated. When they were, rival agencies failed to share the information. “Imagine being taken care of in a hospital with a collection of good specialists—competent, cooperative, conscientious—with no attending physician managing the case,” says Philip Zelikow, the executive director of the 9/11 commission. “And you begin to get a little more of a feel for this.”

Time and again, clues were ignored. Both President Bush and National-Security Adviser Condoleezza Rice have said that no one could have imagined that hijacked airliners would be used as weapons and flown into buildings. The truth is it was a known possibility within the intelligence agencies years before 9/11, and one that an F.B.I. agent warned of in the weeks leading up to the attacks. A supervisor, working in the bureau’s Minneapolis office, was not allowed by headquarters to further investigate Zacarias Moussaoui, a French national of Moroccan descent, who had been detained by the F.B.I. when officials at a local flight school he attended became suspicious of him. The supervisor in Minneapolis warned a headquarters agent two weeks before the attacks that he was “trying to keep someone from taking a plane and crashing into the World Trade Center.”

And the failure wasn’t strictly an American one. While the analyses by the 9/11 commission and other American entities inevitably focus on the C.I.A. and F.B.I., snippets of the conspiracy brewing before the attacks have surfaced in separate investigations in Germany, Spain, Great Britain, and the Persian Gulf. We now know that much information that might have proved valuable, that might have prevented 9/11, either was never passed on to the proper authorities or got lost in the bureaucratic shuffle.

German intelligence agents monitoring Islamic fundamentalists in Hamburg, for instance, attempted to investigate one of the 9/11 hijackers after wiretapping a call in January 1999—a full two and a half years before the Twin Towers fell. The Germans now confirm they mounted a covert operation spanning several years and code-named Operation Zartheit that was intended to flush out Islamic extremists in Hamburg. A program of surveillance and wiretaps led to the identification of two of the eventual hijackers, including the ringleader, Mohammed Atta.

But because of the same kinds of legal restrictions that frustrated American counterterrorism specialists, the Germans decided they did not have enough evidence to persuade a parliamentary commission to approve wiretaps on the group (later known as the “Hamburg cell”) who lived in an apartment on Marienstrasse. A lone C.I.A. agent, the Germans disclose, attempted to work alongside them, but their requests for greater information and cooperation from the C.I.A., they claim, came to naught.

As one studies the missed opportunities, it sometimes seems the world’s intelligence agencies did the most difficult things best and the simplest things worst. Heroic individual efforts led to the identification of obscure Islamist suspects, including some of the eventual hijackers, yet time and again nothing came of such feats. Rivalries, interagency squabbling, and countless bureaucratic hurdles kept essential pieces of information from being shared. The story of 9/11 is one of gaping holes in the safety net that was supposed to have stopped the terrorists; of government agencies and those who ran them refusing to move beyond their histories and egos; of leaders failing to heed the warnings of their own experts, no matter how loudly the alarm bells were sounding. It is, above all, the story of a vast, sophisticated defense system that failed to adapt to a new enemy and to accept the obvious and terrifying threat it posed. To this day, many say, nothing has changed.

I. Tumult and Discord

By the mid-1990s, the Cold War was long over, and the battle for Langley’s soul had begun. Budgets were slashed. Overseas stations were shuttered. Many say the agency became more reactive than proactive. After the 1991 Gulf War, for example, Robert Baer told his bosses that he wanted to stay in touch with those leading the opposition to Saddam Hussein and “all the crazies … but they said, ‘The war is over. We don’t need to see these people. We don’t care what they do,’” he says.

Morale had plummeted because of the 1994 revelation that Aldrich Ames, an experienced counter-intelligence officer, was a Soviet mole, whose treachery had resulted in the deaths of 10 Soviets working for the C.I.A. The morale problem was compounded by two unpopular choices for D.C.I., who heads the C.I.A. First, from 1993 to 1995, there was the short, unhappy tenure of James Woolsey, who had spent a quarter-century working as an attorney and as an influential counsel to the Senate Armed Services Committee. He had served on a number of government commissions, but had no hands-on intelligence-gathering experience, and he clashed repeatedly with Dennis DeConcini, head of the Senate intelligence committee. Then there was the even shorter and unhappier tenure of John Deutch (1995–96). Outside Langley he was known as the D.C.I. who left highly classified documents on a home computer; inside Langley he was scorned as the man who prevented spies from being spies. His “Deutch Rules” prohibited agents from using “dirty” assets—those with shady backgrounds or worse. A noble idea. Unless you’re in the spy business, where the best intelligence tends not to come from Boy Scouts and nuns. “That is the advantage of living overseas and dealing with these people day to day,” Baer says. “You consider the whole range of activity that they are engaged in, including lying to you.”

Increasingly, Langley was lacking in streetwise spies. Agents were avoiding risky field assignments for desk jobs, preferably in the more cushy foreign embassies, where the main venues for recruiting “assets” were cocktail parties. “Although large numbers of new and old case officers were pleased to go to places of extreme danger and difficulty like Afghanistan and Iraq, others would often have what appeared to be a more provisional or temporary commitment to a career in the agency and they would say things like ‘I don’t want to go [to a Third World country], because the default position there is diarrhea,’” John MacGaffin says. “Or they would say, ‘Is that station really going to be career-enhancing?’”

By the 1990s the C.I.A.’s ability to gather “humint,” or human intelligence, had been seriously damaged. Former C.I.A. station chief Milt Bearden pointed out to national-security writer James Bamford (for his 2004 book, A Pretext for War) that in 1991 the Moscow station chief, David Rolph, found out about the coup against Mikhail Gorbachev from an embassy colleague only the morning after it had started. Similarly, during the Gulf War, the C.I.A. had no one in Iraq who was able to provide useful intelligence.

“We stopped being a world service,” says Baer. “And even when they did attack us, in [the World Trade Center bombing of] ’93, it was dismissed as an anomaly.… There was also a good degree of bigotry: ‘These people are ragheads.’”

By 1997, Langley was in the throes of a major brain drain. Scheuer explains: “They called it a buyout program through the whole federal government, and they thought they were going to get rid of the deadwood. What happened was they lost the age-40-to-48 group of very strong potential senior officers, those people who couldn’t stand the bureaucracy anymore. They couldn’t stand the crap, so they retired, and we lost a whole generation.”

Bearden, who retired in 1994, puts it more personally: “Here I am, at age 54.… Am I going to put up with this shit—from some bozo like John Deutch—for one more fucking minute?”

Almost everyone liked George Tenet, an affable backslapper and gifted Washington insider. When President Clinton appointed him D.C.I., in 1997, his philosophy was “to stop beating them—and to hug them.” The son of Greek immigrants who owned a diner in Queens, New York, “he was ambitious,” recalls Baer, who attended Georgetown University with Tenet. “Coming from Queens, going to Georgetown was a trajectory of most of my friends. Blue-collar. New York. Smart kids. Georgetown was a stepping-stone. Like it was for Clinton.”

Baer adds, “George Tenet is someone who understands Washington, understands what it is to get along. He understands budgets, he understands how to schmooze with the politicians. He knows how to make them feel comfortable. That is how he became the director.”

Tenet had allies on both sides of the Senate, having served on the staffs of a Republican (John Heinz) and a Democrat (Patrick Leahy) before becoming staff director of the Senate Select Committee on Intelligence (S.S.C.I.). A stint on Clinton’s “national-security transition team” led to a senior position at the National Security Council. He went to the C.I.A. in 1995 as Deutch’s deputy. When Tenet became D.C.I., “we were delighted,” says Richard Clarke, who had known him for years. “It meant that we didn’t have to fuck around with the rest of the C.I.A. We could just call him.”

Inside the C.I.A., that came to be seen as precisely the problem: Tenet was too eager to please the White House. “George is the ultimate team player, and that’s a strength and also his downfall,” says MacGaffin. He adds that if he were to tell Tenet that, “he’d probably hug me and then I’d fold and forget it or think maybe that I was wrong.”

In addition, Tenet’s lack of field experience caused some C.I.A. officers to mutter he was a “career staffer.” But even Tenet’s greatest doubters considered him an improvement over Deutch. “I had known Tenet a long time,” Scheuer recalls. “When I worked on Afghanistan, in the 1980s, he was chief of the S.S.C.I. staff, and we briefed him every six weeks for a couple of years. So I was very familiar with him. He’d come by, flop down on the couch, and talk.”

Burly and bright-eyed, with dark Mediterranean features, Tenet was a man’s man, slapping backs, talking sports, and smoking cigars. (After suffering a heart attack in the early 90s he just sucked them.) “It might be a little unfair to say,” says a C.I.A. insider, “but it’s probably close: he sort of had a frat-boy attitude. Generous with his time. Curious. Gregarious.”

More important, Tenet rejected Langley’s malaise and was determined to rebuild the agency. He hired Jack Downing, a 57-year-old Harvard graduate and veteran C.I.A. officer, as the new head of the D.O. (The C.I.A. is divided into two parts: the Directorate of Operations, or D.O., which handles the spies and includes the Clandestine Service, and the Directorate of Intelligence, or D.I., which is made up of the deskbound intelligence analysts.) Downing spoke Russian and Chinese and had served as station chief both in Moscow and in Beijing. But his traditional career as a Cold War spy did little to prepare him to deal with the new, terrorist threat. “Downing was a Marine,” says Scheuer, “and then he was a very, very successful officer during the Cold War, but he didn’t have a clue about transnational targets, and he didn’t like analysts,” who made up a large part of Scheuer’s staff.

Tenet set about a massive recruitment drive for the D.O.’s Clandestine Service, but unfortunately the training of these new spies remained very much old-school: they were taught how to operate undercover in European embassies, but not how to infiltrate Islamic terrorist cells.

“Tenet’s a very good man. He got this [terrorism] thing early,” Scheuer says, acknowledging the new D.C.I.’s early support for Alec Station. “He’s very smart. When he was on TV with the 9/11 commission, every one of those guys complimented him on how he got along with everybody. [But] my feeling is that Mr. Tenet is a staffer, and he didn’t have the mind-set to make people do things they didn’t want to do.”

While sending internal memos about being “at war” with bin Laden, a war for which “no resources or people should be spared,” Tenet decreased the budget and barely increased the number of staff in the CTC, to which Alec Station directly reported. MacGaffin says the problem was that Tenet could never bring himself to take money or people from old programs to support new ones. “When I was strategic-planning chief, I suddenly realized I was the most important person in the Directorate [of Operations],” recalls MacGaffin, “because … I did the evaluations, money, and personnel. I mean, I owned them all. I did the ‘Where from?’ It is very easy for anybody to say that we’re going to move $10 million over there, but the real impact comes when you say I’ve decided to take it from here. What we’re going to do with it is decided by ‘Here’s a new problem: we’re going to declare war on al-Qaeda.’ George had difficulty with the ‘Where from?’”

In 1996, Alec Station got a break when a “Mr. Walker” (C.I.A. argot for a walk-in) entered a U.S. Embassy in Africa. Like many embassies, this one housed C.I.A. officers as well as diplomats. Mr. Walker, whose real name was Jamal Ahmed al Fadl, had spent time in the U.S., was recruited for the Afghan war in the 1980s at a mosque in Brooklyn, and became one of bin Laden’s business agents. But he defected to the U.S. when bin Laden discovered he had skimmed more than $100,000 from al-Qaeda. The information al Fadl provided detailed bin Laden’s personality and plans.

In May 1996, the station got an even bigger break—from, of all people, Osama bin Laden himself, when he moved to Afghanistan from Sudan, which was being pressured by various Western and Arab governments to stop giving sanctuary to terrorist organizations. “It was a godsend for him and for us,” Scheuer says. “In Afghanistan we had immense amounts of expertise. We had assets to contact. We had knowledge of the ground. We had topography. It’s a huge place, like Texas, but at least we were familiar with it. Sudan was not that kind of place.”

For the first time, Alec Station had bin Laden firmly in its sights. Part of his family lived 12 miles outside Kandahar, in a secluded compound called Tarnak Farm. Composed of 80 mud-brick and concrete buildings—apartments, a mosque, a medical facility—Tarnak Farm was protected by armed guards, a 10-foot-high wall, and forbidding desert. But its residents, including bin Laden himself, came and went as they pleased. “Osama was like the blue-collar guy,” Scheuer says. “He’d grab his lunch bucket in the morning, kiss the wives, go out the door, drive to Kandahar, do his business, and come back at the end of the day.”

By late 1997, Alec Station had come up with a plan to snatch bin Laden and fly him to an Arab country or to the United States to stand trial. As The 9/11 Commission Report has noted, “No capture plan before 9/11 ever again attained the same level of detail and preparation.” The operation depended on local Afghan tribesmen to overcome the Tarnak Farm guards, enter the compound, grab bin Laden, and spirit him away to a desert site. Later they would hand him over to a second group of tribesmen, who would take him to a landing zone for a rendezvous with a C.I.A. plane that would fly him out of the country. The agency ran four complete rehearsals of the operation in late 1997 and in March and May 1998.

In February 1998, bin Laden upped the ante, arranging for a London-based Arabic newspaper to publish what he called a “fatwa”: “Crimes and sins committed by the Americans are a clear declaration of war on God,” he wrote. “To kill Americans and their allies—civilian and military—is an individual duty for every Muslim.” Alec Station issued an internal report noting, “This is the first religious ruling sanctifying such attacks.” Around that time, in a different report, the station warned: “Sooner or later, Bin Laden will attack U.S. interests, perhaps using WMD.”

Scheuer believed the Tarnak Farm plan was “the perfect operation,” and Gary Schroen, the lead C.I.A. officer in the field in Islamabad, agreed. Schroen cabled headquarters in May 1998 that the plan was “almost as professional and detailed … as would be done by any U.S. military special-operations element.” He gave it about a 40 percent chance of succeeding.

Others were more dubious, including the commander of Delta Force, the commander of Joint Special Operation Forces, and, most important, the higher-ups at the C.I.A., who worried not only that innocent civilians, including women and children in the compound, might die but that, if bin Laden himself were killed, the operation would smack of an old-style C.I.A. assassination. Over at the White House, Clinton’s national-security adviser, Sandy Berger, speculated that the evidence against bin Laden was still sketchy; if he were brought to trial in the U.S., he might be acquitted.

On May 29, Scheuer was told by his C.I.A. bosses that they were going to “stand down on the operation for the time being.” Some at the C.I.A. thought the decision had been made by Berger or at the Cabinet level, but Tenet subsequently told the 9/11 commission that he had made the call, on the advice of his chief operations officers. According to Berger, the plan was never presented to Clinton.

Scheuer was furious and still is about what he sees as a golden opportunity lost: “We had more intelligence against this man and organization than we ever had on any other group we ever called a terrorist group, and definitive and widely varied across all the ends, and I could not understand why they didn’t take the chance.”

That spring, according to Scheuer, Alec Station was going to be disbanded and its operations folded into a branch office. Tenet found out about the decision and overruled it.

Bin Laden finally got Langley’s full attention on August 7, 1998, when two U.S. Embassies in East Africa were bombed. The first explosion, in Nairobi, Kenya, killed 213 people and injured 5,000; the second, in Dar es Salaam, Tanzania, occurring about five minutes after the first blast, killed 11 and wounded 85. Both were carried out by trucks packed with explosives.

Alec Station, which had been monitoring an al-Qaeda cell in Nairobi for a year, quickly fixed the blame on bin Laden. “After that, there was a huge amount of impatience at the White House,” says Daniel Benjamin, head of the N.S.C.’s counterterrorism team in the Clinton administration. Toward the C.I.A., especially, “there was a sense of ‘Come on, get on with it, do something.’”

One day after the embassy bombings, at a principals’ meeting at the White House (attended by agency heads and other top officials), Tenet reported that bin Laden and other terrorist leaders would gather at a jihadist training camp near the town of Khost, Afghanistan. Clarke turned to Tenet and asked, “You thinking what I’m thinking?” Tenet nodded. The principals quickly reached a decision to attack the camp, and the military was ordered to prepare a top-secret plan.

On August 20, 79 Tomahawk cruise missiles, fired from navy ships in the Arabian Sea, pounded the training camp near Khost, and al Shifa, a pharmaceutical plant in Khartoum, Sudan, which the C.I.A. had suspected was being used by bin Laden to produce VX, a deadly nerve gas. Some 20 to 30 people were killed, but bin Laden and other terrorist leaders were not among them.

The reaction in the U.S. was skeptical. Occurring just days after Clinton had admitted on national television to his affair with Monica Lewinsky, many compared the bombing to the 1997 film Wag the Dog, in which the president creates an imaginary war to divert the public’s attention from a sex scandal. Senator Arlen Specter, a Republican from Pennsylvania, wondered about a “diversionary motivation” for the attacks, and John Ashcroft, then a Republican senator from Missouri, referred to a “cloud over this presidency.” The 9/11 Commission Report states that “the failure of the strikes, the ‘wag the dog’ slur, [and] the intense partisanship of the period likely had a cumulative effect on future decisions about the use of force against Bin Laden.”

In August and September, Clarke wanted to follow up with a plan which included more missile attacks, but the Small Group of principals (Berger, Shelton, and Defense Secretary William Cohen, among others) were not persuaded that they would be effective or that there was a promising target.

In mid-December, the Small Group met to discuss intelligence that bin Laden was planning to bomb the American Embassies in Qatar and Ethiopia. It considered sending a Special Ops team into Afghanistan to snatch him or one of his top deputies, but this idea didn’t generate much enthusiasm from an administration eager to avoid another “Black Hawk Down”—the 1993 fiasco in which 18 army rangers were killed in Somalia on a mission to capture two lieutenants of a renegade warlord.

Before the end of the year, the C.I.A. had received reports that bin Laden would be at a particular house in Kandahar. An urgent teleconference of senior officials was arranged to discuss a new missile attack. But the principals again expressed concerns over the intelligence, and possible collateral damage, and decided against the strike. Feeling they had missed another huge opportunity, Scheuer said, he was so upset that he was unable to sleep.

In February of 1999, Alec Station believed it had reliable evidence that bin Laden was spending much of his time at camps near Kandahar, far enough from the city that civilian casualties would not be an issue. At one of the camps an aircraft from the United Arab Emirates was spotted. (The U.A.E. visitors had come to the desert camp to hunt with falcons.) Through intelligence from the local tribesmen, it was determined that bin Laden would be in the larger camp on February 11, and a military strike was prepared but never launched. It was once more determined that the intelligence was unreliable, and the principals worried about killing an Emirati prince. By February 12, bin Laden was gone.

Yet another opportunity arose in May of 1999, when Alec Station received information that bin Laden would be in and around Kandahar for five days. The reporting appeared solid and detailed, the missiles were in place, and everything seemed like a go. “This was in our strike zone,” said a senior military officer. “It was a fat pitch, a home run.” But earlier that month, outdated intelligence had caused the United States to mistakenly bomb the Chinese Embassy in Belgrade. It appears that Tenet’s assessment that the intelligence had only a 50/50 chance of being accurate helped kill the operation.

Scheuer became more and more furious each time there was a failure to act on the intelligence supplied by his unit. “[We had] consistently good information in terms of targeting Osama bin Laden,” he says. In a September 2004 letter to Congress, Scheuer wrote that Alec Station had given the government about 10 chances to capture or kill the terrorist leader.

But Clarke disputes such claims: “You said Mike Scheuer was saying there was a lot of intelligence. There wasn’t. They never penetrated al-Qaeda.”

That, Scheuer believes, is par for the course with Clarke. “There was a consistent pattern of people playing down the quality of intelligence,” he says. “When I went to Clarke’s office, I was the junior guy there. And so, shamefully, I never said, ‘These guys are full of shit.’ You know, this isn’t the best information in the world, but you’re not going to get any better.”

Clarke counters that “Mike Scheuer, when he was running Alec Station, wasn’t a great manager. I think he got very emotionally involved in the topic and expected everybody to just drop everything and give him everything he wanted right away. And he got very frustrated by the internal C.I.A. bureaucracy denying him things, and thought that they were responding to the White House, which was the exact opposite. There are skill sets that you need to get the bureaucracy to do things when you’re a mid-level manager. He didn’t have any. He would just sort of pout and rant.… He came off as a madman.”

Scheuer speculates about Clarke’s lack of support: “He thought he knew more about our business than we did.… I very rarely run into anybody in a senior position who gives any consideration to what happens if we don’t do something. They always think, What if we do? If we do this and we fail, the U.N. is mad at us. The French will complain. The Washington Post will be mad. The Senate will want to hold hearings. I have never heard anyone say, ‘If we don’t do this, 50, 60, or 3,000 Americans are going to die.’ It’s entirely a risk-averse culture.”

But Clarke says it was not a lack of political will or a reluctance to act on the part of the White House or N.S.C. that was responsible for killing the operations Scheuer was so eager for. It was Tenet and his top men, Clarke implies, who stopped them. “Anytime anybody [at C.I.A.] ever brought a proposal to do anything to the White House, we approved it,” he says. “Lack of political will would suggest that they brought proposals, that they were ready to do things, and that we said, Nah, don’t do it. We never rejected. C.I.A. would reject them in-house because in some cases the information was wrong or they thought it was too risky, or whatever.”

Scheuer blames George Tenet, as well. “I think Tenet got it, but I also think that the measure he used [to decide] whether or not to act was not: ‘Does this protect the American people?’ His measure was: ‘What’s the political impact on the president? What will the Europeans say? Will this make the Muslims more mad at us? Will this get the agency criticized for assassination by Oprah or The Washington Post?’”

Some who served in the Clinton White House have cited a reluctance on the part of the military to act. One former senior official told the London Sunday Times that “the Pentagon did nothing. They were paralyzed by fear that something might go wrong like it did in Somalia. ‘Gun shy’ is not putting it hard enough.” Expressing his disappointment over the issue, General William Boykin, the current deputy undersecretary of defense for intelligence, told the 9/11 commission: “Opportunities were missed because of an unwillingness to take risks and a lack of vision and understanding.” In fact, General Anthony Zinni, the head of the U.S. Central Command, was against the follow-up missile strikes to get bin Laden.

Another problem was the lack of cooperation between the C.I.A. and the F.B.I. Both agencies had counterterrorism units, but they operated entirely independently. Some call the divide between the C.I.A. and the F.B.I. “the Chinese wall.” The reasons for it were half bureaucratic, half legalistic: The F.B.I. gathered evidence domestically and legally. The C.I.A. steals secrets in foreign countries by any means necessary. The F.B.I. catches bank robbers, went the saying, the C.I.A. robs banks. The F.B.I. didn’t want the C.I.A. to “infect” its legal cases; C.I.A. officers thought F.B.I. agents were glorified beat cops.

The tension between the two perhaps reached its high point under D.C.I. Woolsey, during the Aldrich Ames affair. Although the C.I.A. had detected Ames, the F.B.I. aided the investigation and arrested him. It seemed that a new era of cooperation was about to begin. Then, Woolsey claims, F.B.I. director Louis Freeh pulled a fast one. “We had an arrangement with Freeh that we would have a joint press conference announcing the arrest,” he says. “[But] the F.B.I. backed out of doing it jointly, made its own announcement, and took its case to the Hill, saying that the C.I.A. had not cooperated at all, and that the bureau should control all counter-intelligence.” An F.B.I. spokesman denies that the F.B.I. had been anything other than laudatory in its comments toward the C.I.A. in the wake of the Ames case.

After Woolsey left, there was a huge effort to mend fences. John MacGaffin, 64, a gregarious Irishman known as “Big John,” spent three decades at Langley. After bumping heads with Woolsey, during the Aldrich Ames bloodletting, he left the agency, only to receive a call from Freeh. “I’m not interested in doing liaison between C.I.A. and F.B.I. and their problems,” MacGaffin told Freeh. “Because God created those.”

Once hired, as a senior adviser, MacGaffin encountered many hurdles, among them that the F.B.I. was, in essence, “56 field offices with a headquarters attached.” Each was its own fiefdom. And, although the F.B.I. had some 12,500 special agents, only around 50 worked in counterterrorism. MacGaffin recalls that their attitude was “We don’t do intelligence. MacGaffin’s trying to just turn us into another C.I.A.”

The F.B.I.’s top counterterrorism officials did not welcome MacGaffin’s arrival and his unsolicited advice. “The F.B.I. didn’t talk to anyone,” says Daniel Benjamin. “It was a chronic kind of behavior. These guys just didn’t talk.”

“I didn’t really like MacGaffin,” says Dale Watson, a Southern gentleman who spent more than two decades as an F.B.I. agent and became its senior counterterrorism official. “It’s difficult for outsiders to come [into the F.B.I.] and be accepted and not be a threat to somebody. He had some of that. His ideas were very strong and opinionated.… And a lot of people said, ‘How dare you? You’ve never worked a case inside the United States. You don’t understand how the law works.’”

Watson was the first F.B.I. agent posted to the CTC as part of an agent-exchange program. In 1995 he was working in Kansas City, investigating the Oklahoma City bombing, when his boss at the F.B.I., assistant director Robert “Bear” Bryant, “calls me and says, ‘Hey, I’ve got a good job for you.… We’re trying to do something different with the agency.’”

“I’m not interested,” Watson replied.

Weeks later, Bryant called Watson again. “This is a good job,” he said. “We’re going to assign somebody over to the CTC. And they’re going to send somebody over to the bureau.”

“I am not interested,” Watson replied, well aware that such an assignment was tantamount to career suicide. “I don’t like those people. I don’t know those people. And I don’t want to go over there.”

A few weeks later, Bryant called again. “I put you out there,” he said, referring to Kansas City. “And I’ll take you back any time I want to. Have a good evening.” Bryant hung up.

Watson arrived at the CTC in June 1996, having “left my fingernails all along the interstate.” He worked right alongside Mike Scheuer. “I’d be lying if I said everybody threw a party for me when I got there,” Watson says. But both sides endeavored to get along. And Watson and MacGaffin settled into something like a friendship.

With Freeh’s blessing, MacGaffin, Watson, and Bryant tried to increase cooperation between the two intelligence behemoths. There were monthly meetings of the so-called Gang of Eight, composed of four top C.I.A. officers and four F.B.I. executives. “Let people of goodwill get together,” went the credo, “and they’ll figure it out.” MacGaffin remembers a powwow with Tenet, Freeh, and others at which they speculated, “What if we rigged something dramatic and took all the counterterrorism part of the agency and the counterterrorism part of the bureau … and organized them exactly the same way, so they mirror each other, with great big pipes between the two, so there’s a free flow of [information] … And then we ran out of wine or something. We never did it.”

Fitting the Chinese Wall with “great big pipes” through which information would flow freely was a great idea. “Then the mattress mice got in the way, as they always do,” MacGaffin says. “And O’Neill was a great big mattress mouse when it came to finding bureaucratic obstacles he could use to further his interests.”

That would be the F.B.I.’s counterterrorism chief in New York, John O’Neill, known as a hard-nosed Jersey guy who favored double-breasted suits, drinking at Elaine’s restaurant in Manhattan, and tough talk. “I am the F.B.I.,” he’d say. “Who the hell are you?” O’Neill was the F.B.I.’s version of a rock star, having spearheaded counterterrorism investigations throughout the Middle East and Africa. “The Big Kahuna,” Elaine Kaufman, who owns the famed Upper East Side hangout for journalists and law-enforcement big shots, called him.

As much as anyone, perhaps, O’Neill grasped the al-Qaeda threat. “This man is not a financier,” O’Neill told Richard Clarke in the mid-1990s. “[He] is building a worldwide terrorist network based out of Afghanistan. The point of which is [to go] after the United States.”

But O’Neill could be hostile, territorial, and paranoid. From the start, he wanted no part of Alec Station, and balked at the Gang of Eight’s plan to swap counterterrorism deputies. He assented only after Bryant told him, “Either you take the deputy or you leave—because that’s the way we’re going to do it.” O’Neill’s new deputy from C.I.A., Jeff O’Connell, hadn’t wanted to switch teams, either, and did so only after the C.I.A.’s other candidate retired rather than work with the F.B.I.

O’Neill and Scheuer bickered early and often. “Mike was working 20 hours a day,” recalls Watson, who liked and admired Scheuer. He pauses. “Mike was a zealot about this. I think he probably rubbed John a little bit wrong when John would say, ‘If you’re gonna catch this guy, we’re gonna bring him back here. This is the F.B.I., and we’re gonna prosecute him.’”

The Scheuer-O’Neill rift was a microcosm of the interagency disconnect. MacGaffin explains: “O’Neill wanted to put someone in jail because they committed a crime. Scheuer’s saying, ‘Whoa, you don’t understand, this is much bigger than that.’” (Scheuer’s and C.I.A.’s instinct would be to “turn” the suspect and send him back to penetrate al-Qaeda.)

After 9/11 the issue of whether the F.B.I. had intentionally withheld information from the C.I.A. or vice versa became white hot. Some say there were such cases; some say the problems were caused by people who refused to change their ways. “There were not too many forward thinkers who understood that we needed to change,” Watson says. “That was the rub.… They would say, ‘That’s the way we’ve always done it. This is our bread and butter.’ I’d say, ‘That’s our bread and butter. But the F.B.I. will forever be changed if the federal building blows up in Portland, Oregon.’”

In the spring and summer of 1999, Tenet was concerned enough to make some major personnel changes. He removed Scheuer as head of Alec Station. Dale Watson felt that it had all become too much for Scheuer. “Everything’s not a crisis. Everything’s not a fight,” Watson says. “You can’t survive doing that every day. He’d been in there for three years, and that’s a burnout job.”

The new head of Alec Station was “Rich,” a key assistant on Tenet’s staff. Rich had had experience with Islamic radicals in a prior posting, in Algeria, where they had staged a violent uprising. He was just as heated up over bin Laden as Scheuer had been, but obviously less likely to cause the kind of friction that would discomfit the D.C.I.

A second change was the appointment of Cofer Black as new head of the CTC, under whose purview Alec Station directly fell. Tall, balding, with owlish eyeglasses, Black was an old-school, covert-ops man. He had spent much of his career in the former British colonies of Africa, where he eventually became station chief in Khartoum. Many colleagues noted his macho, swashbuckling statements, all delivered in a vaguely British accent. “He looked like he walked out of a Cheever story,” says Daniel Benjamin. “He was an incredibly entertaining character. He would make pronouncements that were meant to be dramatic and tough-guy colloquial—to make you think, Oh, my God, this guy’s got brass balls, and he knows the score. He’d say things like ‘No more screwing around. This is going to get rough, and people are gonna come home in body bags. That’s all there is to it. You guys gotta know that.’ He’d talk about body bags all the time.”

The new CTC chief had a personal stake in going after al-Qaeda: in 1995, while Black had been stationed in Khartoum, bin Laden had been in the area and had discovered that the C.I.A. was watching him. In response, he plotted to kill Black. The C.I.A. actually eyed bin Laden’s men practicing the operation on the streets, but Black managed to abort the attempt on his life by having the U.S. ambassador complain to the Sudanese government.

Scheuer says of Black, “He’s outgoing, he’s pleasant, garrulous at times. A little gaseous. It’s common in senior intelligence officers and diplomats where they substitute bravado for thought—that’s my view.” Scheuer believes that Black made up the “Manson family” nickname for his unit and interprets his appointment as head of the CTC this way: “Cofer Black, he arrived, and he was the man, he was the pro from the D.O. [The higher-ups] were thinking, We’ll get rid of these little D.I. people and women.”

Clarke was enthusiastic about Black’s new posting. “He had a reputation as a bit of a cowboy,” Clarke recalls. “So when I was urging Tenet to get someone to run CTC who had balls, he came back to me and said, ‘Well, all right. I found this guy, and I don’t know him personally, but by all reports he’s got big cojones.’ And when he showed up, it was really a breath of fresh air. After a couple of weeks running CTC he came to me and said, ‘Now I understand why you were so mad,’ because basically, according to him, the reason they had no one in al-Qaeda was they’d never tried.”

But Black and Rich’s solution to going after bin Laden was not to focus on penetrating al-Qaeda. Instead, they decided to initiate a series of covert operations with Islam Karimov, the brutal, autocratic president of Uzbekistan, and Ahmed Shah Massoud, the leader of the Northern Alliance in Afghanistan. Karimov was having his own problems with bin Laden, who was funding Islamic radicals in Uzbekistan—they had tried to assassinate Karimov in February by attempting to blow up his limousine. Massoud, operating in the Panjshir Valley, in the extreme Northeast of Afghanistan, was the most important holdout against the Taliban regime, bin Laden’s sponsor in Afghanistan.

The White House had reservations about using either as a partner—Karimov because he was infamous for human-rights abuses, such as boiling his enemies to death, and Massoud because he financed his resistance movement partly by smuggling heroin into Europe. An even bigger problem was that bin Laden spent most of his time in and around Kandahar, far to the south of either Uzbekistan or the Panjshir Valley. Massoud was apparently quite candid with the C.I.A. about the limited help he could provide. When the plan to capture bin Laden was proposed with the caveat that he not be killed, according to Gary Schroen, Massoud winced and said, “You guys are crazy—you haven’t changed a bit [since the 1980s and the Afghan-Soviet conflict].”

But that did not stop Black and Rich from flying in to see Massoud with briefcases stuffed with a quarter of a million dollars—or from starting a joint operation with the Uzbek military to create a counterterrorist strike force, funded and trained by C.I.A. Unfortunately, none of this produced much in the way of meaningful intelligence on bin Laden. “I was in Afghanistan in 1999, and I had a long discussion with Massoud about what the agency was doing,” says veteran C.I.A. man Reuel Gerecht. “He was amused by me. [Because] we were not serious.… People would fly in for a day or two, then fly out before the food could have an effect on them. They were essentially trying to set up listening posts [to monitor Taliban communications]. That’s probably their major achievement.”

Matters did not improve with Tenet’s third and most important personnel change—replacing Jack Downing as the head of the D.O. with Downing’s number two, James Pavitt. The white-haired Pavitt maintained a stiff posture and wrote with Mont Blanc pens.

“Poor Jim had this [habit that] just made every D.O. officer’s toes curl when he’d talk in public or in a D.O. staff meeting,” recalls a C.I.A. source. “[He’d refer to] ‘my case officers’ and ‘my station.’ If you notice, Milt Bearden never said ‘my case officers,’ he’d say ‘the people I work with’ or ‘my colleagues.’… Poor Jim, it’s basic leadership.”

Pavitt, one of the key C.I.A. brass who had persuaded Tenet to call off earlier strikes against bin Laden, including the 1998 Tarnak Farm kidnapping plot, had an extremely conservative view about undertaking covert operations. “As a younger guy growing up in the D.O. he saw all his bosses involved in controversy and scandal,” explains Clarke. “And he learned the lesson as to why they got involved in controversy and scandal—it’s because they had done things, they were activists. Or they were responding to White House pressure to be activists.”

If Clarke had had high hopes at first, he soon became frustrated with the lack of results from this new team and their new strategies to disrupt al-Qaeda which Tenet called “the Plan.” Clarke blamed Pavitt primarily. “Imagine poor Cofer as the meat in the sandwich or the thing in the vice,” he says, “because I would be pushing from one end, Tenet would be pushing from the other … but in order to get stuff done Cofer had to go through Pavitt, and Pavitt would be slowing it all down. And so here’s poor Cofer, wanting to do what I’ve asked him to do, being urged by Tenet—in broad terms—to do this kind of stuff, but being unable to do it, because of all the lawyers who worked for Pavitt, all the budget people who worked for Pavitt, all the layers of bureaucracy. And the other thing is, quite frankly, Cofer would say to me, ‘My next job is going to be decided by Jim Pavitt.’”

Clarke blames Tenet for not holding Pavitt responsible for the lack of results: “How do you explain the fact that Tenet didn’t turn around to Pavitt and the folks in the D.O. and say, ‘Your performance is unsatisfactory, and if you can’t deal with bin Laden, if you can’t kill him, if you can’t disrupt the organization, then I’ll fire you’?” Clarke says he explicitly debated with Tenet about getting rid of Pavitt: “It would be something like … ‘Either get rid of Pavitt and find somebody who can do it, or take the issue away from him.’ And what I would get back from him is ‘I know, I know, I know, you’re right … but you have to understand that the major problem I’m dealing with as D.C.I. is the morale of my employees.… My philosophy is to stop beating them. And you want to go get them to do things. So do I. But when they don’t do things, you want to fire them, and I want to persuade them.’”

Black believes that the problem was a lack of resources. He testified before the 9/11 commission that “the big bottom line here is … we didn’t have enough people to do the job. And we didn’t have enough money by magnitudes.… The people that did this are heroes, and we didn’t give them what they needed to fight and win. It’s that simple.”

That was partly the case. At the same time Black was supposed to execute the Plan, he was being asked to cut the operating budgets of the CTC by 30 percent. Clarke says, “There’s some truth to the fact that they didn’t have enough money, but the interesting thing is that they didn’t put any of the money they had into going after al-Qaeda. They would say ‘Al-Qaeda, al-Qaeda, al-Qaeda’ when they were trying to get money, and then when you gave them money it didn’t go to al-Qaeda. They were trying to rebuild the D.O., and so a lot of it went to D.O. infrastructure, and they would say, ‘Well, you can’t start by going after al-Qaeda, you have to repair the whole D.O.’… And what I would say to them is ‘Surely there must be a dollar somewhere in C.I.A. that you could re-program into going after al-Qaeda,’ and they would say ‘No.’ The other way of saying that is everything else they’re doing is more important.” (The C.I.A. declined requests for interviews with Black, Downing, Pavitt, and Tenet.)

The real bottom line, many in intelligence say, was that the only way 9/11 could have been stopped was if the C.I.A. had managed to place a mole inside al-Qaeda. The C.I.A. has admitted that before 9/11 they had not penetrated the al-Qaeda leadership, and the agency had acquired little in the way of useful intelligence that could supply the basis for action.

Reuel Gerecht says the C.I.A. was having “mental breakdowns trying to think up how they were going to do these things.” Over and over, old agency hands have claimed that it was simply too hard to get inside al-Qaeda, given the clan, ethnic, and religious ties that bound the organization together. Woolsey says, “Getting somebody in that family is going to be considerably harder even than getting an F.B.I. informant inside a Mafia family here. The K.G.B. was a piece of cake compared to al-Qaeda.… It’s obvious that you’re not going to be able to penetrate even the fringes of al-Qaeda if you’re a younger version of me, a Wasp from Oklahoma, even if I speak some Arabic.”

But, as critics point out, John Walker Lindh, a 20-year-old from Marin County, California, had no trouble whatsoever penetrating al-Qaeda. “He whacked his way in. He’s a whack job, and he whacked his way in,” says MacGaffin. “Could we have? Should we have? Can you imagine someone telling Jim [Pavitt] he wanted to recruit this long-haired guy from California, and we want him to go and sign up?”

II. Lost in Translation

While the budget cuts, intelligence failures, miscommunications, wrongheaded strategies, and ego battles were going on at the C.I.A. and F.B.I., preventing the Plan from going anywhere, another plan was being hatched by a handful of men. “The Planes Operation,” they called it. If we are to believe the testimony Khalid Sheikh Mohammed gave after he was apprehended on March 1, 2003, in Rawalpindi, Pakistan—his testimony was possibly obtained by torture and some of it has been discredited—he was the mastermind of the plan. Kuwaiti by birth, he could have had his pick of jobs in his native country after graduating with a degree in mechanical engineering from North Carolina Agricultural and Technical State University, in Greensboro. But instead, in 1987, he went to Pakistan and Afghanistan to fight the Soviets, alongside a young Saudi financier named Osama bin Laden. How well Khalid Sheikh Mohammed (referred to as “KSM” in The 9/11 Commission Report) and bin Laden knew each other then is unclear, but they traveled in the same circles.

The third key player in what became the 9/11 plot was KSM’s nephew Ramzi Yousef, currently serving 240 years in the U.S. Penitentiary–Administrative Maximum Facility in Colorado for bombing the World Trade Center in 1993. Yousef studied electrical engineering at the Swansea Institute of Higher Education, in Wales. In September 1992 he showed up in New York, where, together with other Islamic terrorists, he staged the first attack on the World Trade Center—an idea Yousef originally developed with Uncle KSM. On February 26, 1993, a van packed with explosives blew up in the World Trade Center’s underground garage; more than a thousand people were injured, and six were killed. Yousef claimed responsibility for the bomb, promising that more would follow unless the United States stopped supporting Israel.

In 1994, Yousef and KSM traveled to Manila, where they helped a group of Afghanistan-war veterans with ties to bin Laden. Here, uncle and nephew concocted the “Bojinka” (slang for “explosion” in many dialects of Arabic) plot, to simultaneously explode bombs on 12 U.S. airplanes over the Pacific. They also planned to assassinate the Pope when he visited Manila, and President Clinton during a visit to the Philippines. To those ends, Yousef’s apartment in Manila was a laboratory. When a fire led the police there on January 7, 1995, they found chemicals, bomb-making equipment, and a laptop that contained the blueprint for the Bojinka plot. Yousef escaped to Pakistan, and KSM to Qatar, but Yousef was apprehended a month later. The Bojinka plot had failed, but the idea of using airplanes against America was still percolating. Bin Laden was ready to take his jihad to the United States. All he needed was a mastermind with big ideas, technical expertise, and international connections. KSM fit that description, and he was about to come bin Laden’s way.

The two men had not seen each other for years, but in 1996 they met in a mountain hideout near Tora Bora, on the border of Afghanistan and Pakistan, to discuss options for a new terrorist campaign. KSM proposed a plan in which al-Qaeda pilots would crash commercial airplanes into buildings in the United States. Although bin Laden would not yet sign on, the Planes Operation was born. By early 1999, KSM had moved to Kandahar to work directly with al-Qaeda, and bin Laden made the decision to go forward with the operation.

KSM and bin Laden agreed that hitting the American economy was probably their best strategy. New York was a target from the start. In the original plan, a total of 10 aircraft would be hijacked on both coasts; 9 would be crashed into buildings, including nuclear power plants; the 10th would be landed by KSM himself. After killing all adult male passengers on board, KSM would deliver a speech to the media, denouncing U.S. support for Israel and repressive Arab regimes. Bin Laden and his lieutenants were skeptical of this last part, but they liked the rest. For targets, the plotters eventually settled on the World Trade Center, the White House, the Pentagon, and the U.S. Capitol. Bin Laden then personally selected four operatives to train as suicide pilots and sent them to prepare at an elite camp in an abandoned Russian copper mine near Kabul.

By the fall of 1999, it looked as though a number of the hijackers Osama bin Laden had selected would encounter problems getting into the United States. But four eager young Arabs had just arrived at bin Laden’s camp from Germany: Mohammed Atta, Marwan al Shehhi, Ziad Jarrah, and Ramzi Binalshibh. They had lived in the West, had good technical skills, were committed to the jihad, and, most important, spoke English. The four had been living in a working-class Hamburg neighborhood for a year or so. They had met at the Al Quds mosque, an institution that expounded the violent overthrow of Israel. “The Jews and Crusaders must have their throats slit,” the imam at Al Quds said in one sermon. The four men had become increasingly virulent in their fundamentalism, and, at the urging of an al-Qaeda recruiter named Mohammed Haydar Zammar, they had gone to Afghanistan. When they arrived in camp, they were invited to a personal meeting with Osama bin Laden.

Three years after the Twin Towers fell, the top officials of the L.F.V., Germany’s provincial security service, remain haunted by their failure to stop what came to be known as the Hamburg cell. The frankest admission comes from Manfred Murck, a veteran investigator who serves as an L.F.V. deputy director. “It’s not that I look back and say, ‘There was something which we missed which would have made a difference,’” he says. “But there are points where we can say, if we had made further investigations, they might have.”

Hunched over the conference table in his utilitarian office, a big, careworn man of 55, Murck draws deeply on his cigarette and sighs. His staff, together with their colleagues in the federal German service, the B.F.V., had been watching Islamic radicals in the city for years. In the months before Atta, Jarrah, and al Shehhi left Germany, in May and June of 2000, to train as pilots in America, the L.F.V. almost got a handle on them. In wiretapped calls with other extremists, the German authorities heard al Shehhi’s voice and Atta’s name.

In retrospect, however, Murck’s people most regret having failed to monitor the Al Quds mosque, which is located on a busy, run-down street in Hamburg’s St. Georg district. Sandwiched between a Chicken Star fast-food restaurant and the Olympic Fitness gym, it occupies the upper floors of a square, concrete building; its main prayer room, an airy hall with white walls and a gold-and-turquoise striped carpet, bears a strong scent of rose water.

A glimpse inside the Hamburg cell’s life at the mosque—the kind of moment German authorities might have witnessed there had they been watching—can be seen in a video of the 1999 wedding of Said Bahaji, one of Mohammed Atta’s roommates at the apartment they occupied on the Marienstrasse. A number of members of the Hamburg cell are visible on the videotape, some wearing suits with buttonhole flowers: not only Bahaji but also Binalshibh, al Shehhi, Jarrah, Mounir el Motassadeq, and Abdelghani Mzoudi, who was also indicted in Germany as part of the 9/11 plot, but later acquitted in part because U.S. intelligence agencies refused to release the transcripts of another al-Qaeda captive’s interrogations. Also shown are two older men suspected of terrorist links, Mohammed Zammar and Mamoun Darkazanli.

The film begins conventionally enough, with the happy couple’s nuptial ceremony. Then the camera pans to Binalshibh, who stands and makes a speech. “It is now as if we were in school, in Arabic lessons,” he begins. “At the end, we have a test. Some will pass this test, [others] will not,” Binalshibh tells his audience. “The problem of Jerusalem is the problem of the nation.… That is also the problem of each Muslim everywhere. At every opportunity and with every jihad, each Muslim must remind his comrades of this.” Quoting a poem, he says that when Israel flew its flag over Jerusalem, “how can you bear these humiliations?… When the tyrants attack you, you will then be a wave of fire and blood.”

Afterward, shining-eyed, led by al Shehhi, Binalshibh, and Mzoudi, the men sing battle songs in honor of Allah in ancient Arabic. Their verses celebrate bloody events from the past, such as Salah el-Din’s defeat of the Crusaders, and promise more for the future: “Our squads have been revolutionized.… Against the heresy, like a volcano, like hurricane and fire, we follow the voice of your call.… We will be aglow with readiness for action. We will crush the throne of the oppressor.”

Another anthem celebrates martyrdom, with its promise of virgins in paradise: “I have arrived into this life, which is only a brief, transitory enjoyment, a journey through, a battle. I am fire and light.… My eyes are full of light, the maidens of paradise belong to me.… These gardens are fragrant, and their aroma are my wounds.… Just like an angel, I sing in the garden and to the fountains. In a garden, better than a thousand lifetimes. And I have not wished for anything more.” The video ends with a chant: “El-jihad! El-jihad! El-jihad!”

Before 9/11, Murck and his colleagues believed that the radicals who spoke out in such places had brought their militancy with them from the Middle East, having “fled their home states precisely because they were more radical.” What neither he nor his colleagues had realized was that such mosques were also the places where secular, beer-drinking students like Jarrah could be indoctrinated to the point where they might be prepared to abandon a love affair for training in Afghanistan for a suicide mission.

Partly, Murck says, echoing complaints often heard from his American counterparts, his group’s failure was a question of resources. After years of pared budgets, he had been forced to reduce his staff: the personnel assigned to the Hamburg L.F.V. fell from 200 at the end of the 1980s to just 122 in the months before 9/11. It was also a question of priorities: before the attacks, Murck had just two investigators and one analyst working full-time on local Islamic militants. (Today, there are more than 40, joined by still more from other German agencies.) The rest of the agency’s efforts were taken up with other kinds of political extremism and organized crime.

Even so, the Germans came tantalizingly close to flushing out the Hamburg cell before 9/11. An internal L.F.V. memo drawn up two days after 9/11 identifies Mohammed Zammar, a 300-pound bear of a man from Aleppo, Syria, as an ardent jihadist who had been to Afghanistan to train and join the jihad. Using many sources, the L.F.V. learned that in 1991 Zammar had received military training in weapons and explosives in Pakistan and had had personal contacts with Osama bin Laden.

Zammar, a father of six, lived on welfare, but in 1996 the B.F.V. was tipped off by Turkish intelligence that he had been traveling the globe to trouble spots: more than 40 journeys in all, to such places as Bosnia and Chechnya. In 1997, German officials say, the B.F.V. launched an operation designed to discover just how serious Zammar and his Hamburg associates were, using the full range of intelligence techniques, including wiretaps and attempts to gather reports from human agents.

This was Operation Zartheit—German for “tenderness”—an investigation of Islamic militants in the Hamburg area that ran for at least three years. It was during Operation Zartheit that German officials first uncovered—but largely failed to appreciate—clues to the Hamburg cell’s plans.

“On 2 Oct 1998 in Turin, Italy,” an L.F.V. memo reads, “three persons of Yemeni origin were arrested in connection with attacks on US interests in Europe by Egyptian Islamic Jihad [the group led by bin Laden’s deputy, Ayman al-Zawahiri, which by this time had joined forces with al-Qaeda]. Italian police searched apartments and found beards, wigs, weapons and contact details for Zammar, with mobile phone number.”

The Germans were also watching a friend of Zammar’s, a Syrian businessman named Mamoun Darkazanli. In September 1998, Mamdouh Mahmud Salim, a terrorism financier, was arrested near Munich, and it was discovered that he had opened an account at a Hamburg branch of the Deutsche Bank for which he had given Darkazanli power of attorney to sign checks. According to another L.F.V. memo, Darkazanli had contact with Wadi al Hage, bin Laden’s former private secretary. (Both al Hage and Salim were extradited to the U.S., convicted in federal court in New York for their part in the 1998 embassy bombings, and sentenced to life imprisonment. Darkazanli lives in Germany, where he has yet to be charged with any crime.)

All this information was shared at the time with the C.I.A., which was becoming increasingly concerned about Islamic extremism in Germany. The agency had an official based in Hamburg who frequently visited Murck and his colleagues at the L.F.V. and also saw contacts at the B.F.V.

The official tried to persuade the Germans to recruit Darkazanli as an agent—a scheme they regarded as preposterous. In the words of one German official, “You cannot recruit a fanatical Arab mujahid.” During these discussions, the U.S. official promised that cooperation between the L.F.V. and B.F.V. and the C.I.A. would be a “two-way autobahn”—that anything the Americans learned about Islamic radicals in Germany would be immediately relayed to their German allies. Tragically, it seems that his promise was not kept.

As the U.S. official’s interest grew, Operation Zartheit was drawing closer to the core members of the Hamburg cell. On January 31, 1999, at a time plans for the 9/11 attacks were likely under way, a B.F.V. wiretap recorded a call to Zammar from a man called Marwan. It now seems certain, officials agree, that he was Marwan al Shehhi, one of the eventual hijackers, who piloted United Airlines Flight 175 into the south tower. The listeners’ suspicions were aroused by an exchange soon after the call started.

“They say you are in Bonn [Germany] at the moment,” Zammar said. “Yes, in Bonn,” al Shehhi replied. In fact, the call was being made from a cell phone traced to al Shehhi’s home country, the United Arab Emirates (U.A.E.). Other parts of the conversation seemed redolent of some kind of conspiratorial code:

Al Shehhi: I’ve heard your mother died.

Zammar: Yes, she passed on. She left me alone.

Al Shehhi: But your father didn’t travel with you? I’ve seen him here.

Zammar: No, my father is here.

“Our desk officer had a certain feeling about that call,” says a senior German official. “You can say it was his nose—not that there was any single statement, but he had a feeling that there could be more behind it.” The desk officer wrote a report, and as a result the B.F.V. asked the C.I.A. for more information about men from the U.A.E. named Marwan, and for help in finding out whom the phone number was registered to. George Tenet has acknowledged that the agency received the name and the phone number, but has not said what, if anything, the C.I.A. did to follow up. “We didn’t sit on our hands,” he said to the Senate intelligence committee, but he declined to say more in open session. However, two German officials separately told Vanity Fair that the Germans’ request failed to draw a reply from the C.I.A. (The C.I.A. declined to comment.)

On September 21, 1999, at 8:33 a.m., Zammar called Atta’s “house of the followers,” at 54 Marienstrasse, and spoke to both al Shehhi and Said Bahaji. German investigators were listening in. From the warm and intimate tone of the conversation, it was clear Zammar and Atta’s roommates knew one another well and had spoken many times before. The B.F.V. had earlier recorded another conversation, between Zammar’s wife and his father, which had already alerted them to the Marienstrasse apartment’s possible significance. During that earlier conversation, Zammar’s father appeared to be exasperated, and after establishing that the wife did not know her husband’s whereabouts he immediately assumed his son was with “those people” at Marienstrasse: Mohammed Amir (Atta), Mounir (Motassadeq), and “Omar”—a name used by Binalshibh. In a September 2001 memo, the B.F.V. said it had information that in February 1999 Zammar had actually been staying in the Marienstrasse apartment with Atta, Bahaji, and Binalshibh. (After leaving Germany in the wake of 9/11, Zammar was extradited to Syria, where he may have been tortured.)

In retrospect, this may have been the moment when German intelligence had its best opportunity to focus on the Marienstrasse cell—yet it didn’t. The senior German security official says that after these wiretapped calls “we had the impression that the people living there were fanatical believers. At the B.F.V., we had to decide whether to ask permission to place a wiretap on the line at 54 Marienstrasse itself. We discussed this every day.” In the end, he says, he and his colleagues believed that they would not be able to persuade Germany’s wiretap commissioners that such a measure was necessary, as there was no evidence that the apartment’s occupants were breaking the law.

Another missed opportunity was Ziad Jarrah’s interrupted journey back to Hamburg from Afghanistan. On January 30, 2000, having left the camps and crossed the Pakistani border, he flew from Karachi to Dubai. While he was in transit, officials became suspicious, because he had stuck a page of the Koran into his passport. Searching his baggage, they found it full of jihadist propaganda videos. Six months earlier, the C.I.A. had asked border-control agencies throughout the region to question anyone who may have been returning from a training camp in Afghanistan.

Jarrah was interrogated at the airport for four hours. He answered questions about Afghanistan and, amazingly, disclosed his plan to train as a pilot in America. But, in the end, he was allowed to fly on to Germany, pausing briefly to buy his girlfriend, Aysel Senguen, an 18-karat-gold ring. By this time, Jarrah had met bin Laden and KSM and agreed to become a martyr. The Dubai authorities duly informed the C.I.A. of Jarrah’s interrogation, German officials say, but the Americans inexplicably failed to pass the information on to the Germans. (A spokesperson for the C.I.A. denies that the C.I.A. had any knowledge of Jarrah prior to 9/11.)

“If we had been given the information that Jarrah had been to Afghanistan and was planning to go to flight school, we might have asked the Americans whether they thought this was normal,” a top German intelligence official says. “If they had asked us, ‘Who is this guy who is learning to fly?’ then perhaps there might have been a different outcome.” They might, he adds, have placed Jarrah under surveillance. “But it was one-way traffic. You gave information, and you got no response.” (According to a spokesperson for the C.I.A., “The notion that the Germans passed us a great deal of information is not supported by the record.”)

The C.I.A. was not the only friendly intelligence service that failed to share vital information with its German counterparts in the years before 9/11. Equally inexplicable, and possibly as harmful, was the behavior of the Spanish anti-terrorist authorities. For much of the 1990s, the Spanish ran an impressive operation against a Madrid al-Qaeda cell, led by Imad Barakat Yarkas, also known as Abu Dadah. Wiretaps on Yarkas’s phone had revealed that he was in regular contact with Zammar and Darkazanli.

Bizarrely, say German officials, this and other information was supplied to the C.I.A.—but never to the people who might have been able to make the most effective use of it, the German B.F.V. “We simply don’t understand why they didn’t give it to us,” says the top German intelligence man. He sighs. “Cooperation between agencies does not always occur in real time.”

Once again, it represented a considerable missed opportunity. Had the Germans realized that Zammar and Darkazanli were directly connected to a terrorist suspect, as opposed to a mere religious extremist, Operation Zartheit might well have shifted into a higher gear. The prospects for stopping 9/11 may have been enhanced, for after the attacks it emerged that Yarkas knew two other German militants—Ramzi Binalshibh and Said Bahaji.

Most damning, Spanish wiretaps which were not made available to the Germans when they might have done some good revealed that Yarkas and his close associate Amer Azizi were involved in planning an al-Qaeda meeting (which they may have attended) in the town of Tarragona in July 2001. At the meeting were Binalshibh and Mohammed Atta, who had flown over specially for it on his last trip outside the United States. The meeting’s purpose, according to the Spanish indictment against Azizi, was to “arrange the final details for the terrorist action they were about to carry out: the day (09/11/01), the targets in the United States and the way the attack should be done.” A few weeks later, on August 27, Yarkas received a call from a British-based terrorist known as Shakur. “We have entered the field of aviation and have even beheaded the bird,” he said.

It wasn’t just the Germans and Spanish who dropped the ball. The British, too, ignored repeated warnings. Since 9/11, some people have come forward to tell how Britain’s domestic-intelligence service, M.I.5, ignored their warnings about Islamic extremists. One was Reda Hassaine, an Algerian journalist. Determined to do what he could to combat militant Islam after several friends were murdered by extremists in his home country, Hassaine infiltrated the Finsbury Park mosque in London, passing on what he learned to both the media and the security services of France, Britain, and, at times, Algeria.

Hassaine began his one-man operation in 1994, the same year M.I.5 disbanded a special section, known as G7, which had been established to monitor Islamic militants after non-Israeli targets in the Middle East and Europe were attacked in the early 1980s. This change, ordered by M.I.5’s first female chief, Stella Rimington, was bitterly opposed by her colleagues: a year earlier, the first World Trade Center bombing had illustrated that Islamic terrorists were very much on the move. Vital continuity and experience were lost, one senior British official says, and even after al-Qaeda claimed responsibility for the 1998 American Embassy attacks in Africa from a fax machine in London, nothing was done to restore the unit.

For Hassaine, this meant that information he was gathering every week was never taken seriously by the only people in a position to do anything about it—the authorities in Britain. At Finsbury Park, he says, the imam, the claw-handed, half-blind Abu Hamza, preached a torrent of hate toward the West. “Every single week there were waves of people going there,” Hassaine says. The shoe bomber, Richard Reid, convicted of trying to blow up an American Airlines flight from Paris to Miami in December 2001, attended the mosque. Abu Hamza himself is now in London’s maximum-security Belmarsh prison, awaiting extradition to America on eleven terrorism-related charges. In the basement of the mosque, Hassaine says, al-Qaeda supporters manufactured false passports and other documentation, and between prayer sessions each Friday “the talk there was only about death—about being killed in the name of Allah, martyrdom, swords, bombs, and Kalashnikovs.”

But at meetings he had with M.I.5, “they didn’t even take notes,” Hassaine says. He had more confidence in an officer from Scotland Yard, but that officer seemed to be hamstrung by his superiors. The handler M.I.5 eventually assigned Hassaine was “young, incompetent, not a guy with whom you can speak properly.” (M.I.5 declined to comment for this piece.)

It is now thought that at least 10 of the 9/11 hijackers stayed in London for several weeks before traveling to America; it is still not known where. Ramzi Binalshibh made several trips to Britain and is thought to have met with the radical cleric Abu Qatada. And as the 9/11 commission makes clear, after Zacarias Moussaoui, still facing trial as the “20th hijacker,” was arrested in Minnesota in mid-August 2001, the F.B.I. sent M.I.5 a request for information about him, because he had lived in London—and moved in the circles Hassaine had infiltrated. A prompt reply to that request might have revealed his close connection with Binalshibh and set other alarm bells ringing. In the event, M.I.5 did not reply to the F.B.I. until shortly after the September 11 attacks.

At Easter 2000, at the very time that Atta and the other pilots were about to learn to fly in America, M.I.5 missed another opportunity to penetrate the European side of the global Islamist web. Niaz Khan, a former waiter from Oldham, near Manchester, was drawn into terrorism by an unconventional route—he needed money to pay $9,000 in gambling debts. At a casino near Manchester, he says, he met two men who “knew the Taliban.” The men promised that, if Khan went to a camp in Pakistan and agreed to undertake a mission, his debts would be paid. At the camp, a walled compound near Lahore, Khan was taught how to smuggle guns and other weapons through airport security, and ways of overpowering aircraft passengers and crew in order to get into a cockpit.

A British newspaper report of Khan’s story claimed that he had been told he would be joining a plot to hijack planes in America and fly them into buildings, but this, Khan says, was inaccurate—he was asked only to join a regular hijacking. After training, he says, he was flown via Qatar and Switzerland to J.F.K. airport, in New York, where, he was told, he would be met by a local al-Qaeda contact, “Babu Khan.” But during his long journey, he had second thoughts: “When I joined, I believed in jihad, because I’d lost money and I was fed up.” Evading Babu Khan, he made his way to Atlantic City and, after making a few more bets, turned himself in to the local police, who swiftly transferred him to the care of the anti-terrorism experts with the Newark, New Jersey, field office of the F.B.I.

Khan passed two polygraph tests “with flying colors,” according to the former F.B.I. agent who handled the case. He declared himself ready to work against terrorism, offering to devise a story to explain his failure to meet Babu Khan, and then to make contact again with the Islamic radicals. “Of course I was ready to do this,” Khan says.

Because he was a British citizen, the appropriate agency to act as Khan’s handlers would have been M.I.5: “We couldn’t work him on foreign soil—that’s why we gave him to the Brits,” the former F.B.I. man says. He and his colleagues made contact with the British and agreed to fly Khan to London’s Heathrow Airport, where he would be handed over. All seemed to go according to plan, and when they arrived at Heathrow two British officials were waiting. The F.B.I. agent flew home and didn’t see or hear from Khan again until 2004.

“So what happened?” he asks Khan. “How long did they speak to you at Heathrow?” The former agent is visibly staggered by Khan’s reply: “Forty-five minutes. And then they let me go. I got on to the tube [subway] back home here to Manor Park. Even after 9/11 happened, I never saw anyone. I got no phone calls, no letters, nothing.”

“I just assumed that when Niaz was turned over the British authorities would have conducted a full investigation. What I would have done is re-inserted him into the community and worked him,” the former F.B.I. man says. “We know that didn’t happen. It’s a real shame.”

III. Consequences

As the millennium approached, intelligence about possible attacks was coming in at a furious pace, and the F.B.I., C.I.A., and White House were on high alert. “We were frantic,” Cofer Black is quoted as saying in Steve Coll’s 2004 book, Ghost Wars. “Nobody was sleeping. We were going full tilt.” On November 30, Jordanian police burst in on an al-Qaeda cell in Amman; beneath the floor of the hideout they found the makings of a massive bomb, which the terrorists intended to use on January 1 to blow up the city’s Radisson Hotel and other sites frequented by American and Israeli tourists. In Port Angeles, Washington, on December 14, a watchful border guard, Diana Dean, noticed a Middle Eastern man acting suspiciously as she was inspecting cars coming off the ferry from Canada. His name was Ahmed Ressam, and he turned out to be a member of a terrorist cell in Montreal; he had trained at an al-Qaeda camp in Afghanistan. When customs agents searched his rented Chrysler, they found enough explosives in the car’s spare-tire well to level a good chunk of LAX airport, which had been Ressam’s plan.

Although authorities would not find out until much later, a third al-Qaeda millennium plot was foiled when terrorists in Yemen overloaded their boat with explosives, sinking it moments before they could blow up the U.S.S. The Sullivans. “We knew nothing—absolutely zip—about it,” says a C.I.A. source. “Now, that told you, crystal-clearly, that the agency had no sources of any value anywhere in that organization. Period. If we had anyone near a circle that mattered, we would have picked up a vibration from the [planned] attack.”

On December 29, Alec Station was contacted by the N.S.A. Amid the storm of pre-millennial “chatter,” the agency had intercepted communications among three Arabic men, each of whom bore some connection to the East Africa bombings—and to al-Qaeda. In early January, the N.S.A. reported, the three men would be part of an al-Qaeda “operational cadre” traveling to Malaysia. Only their first names were known: Nawaf, Salem, and Khalid.

Intelligence picked up Khalid’s trail in Sana’a, Yemen, where he boarded a flight to Dubai, in the U.A.E. In Dubai, while transferring to a connecting flight, he was approached by customs agents, who had been alerted by U.S. officials. While checking Khalid’s documents, agents secretly photocopied his Saudi passport, which revealed that he had recently been issued a multiple-entry travel visa to the United States.

Now Alec Station knew the full name of one of the three: Khalid al Mihdhar. On January 4 and 5 the men met up at the home of Yazid Sufaat, a Malaysian jihadist, on the outskirts of Kuala Lumpur. At this point, surveillance became haphazard. Sufaat lived in a luxury condominium complex near the Sungai Long Golf & Country Club, whose course was a “Jack Nicklaus Signature.” Three days passed uneventfully. As requested, though, Rich provided surveillance updates for Langley’s top officers, the F.B.I., and the White House.

After a few days, Nawaf and Khalid suddenly left Kuala Lumpur on a flight to Bangkok, where, despite some efforts to monitor them, the C.I.A. lost their trail. Roughly two months later, the agency learned from Thai intelligence that “Nawaf” was Nawaf al Hazmi, and that he had traveled to Los Angeles on January 15. (It was later discovered that al Mihdhar had gone with him.) In fact, bin Laden had handpicked al Mihdhar and al Hazmi for the Planes Operation. Bin Laden and KSM had decided that it would be easier for the two al-Qaeda operatives to enter the United States coming from East Asia. They were right. Not until after 9/11 did anyone in the C.I.A. or F.B.I. realize that the two had settled comfortably in San Diego, awaiting orders to join the 9/11 terrorist teams.

The news that al Mihdhar, a known al-Qaeda terrorist, and al Hazmi, who had just attended a highly suspicious meeting with him, planned to enter the U.S. should have been enough to put their names on the State Department’s Tipoff watch list. Unfortunately, Alec Station never passed on the news to the State Department. Or to the F.B.I. James Bamford quotes a senior intelligence official as saying, “We have documents within the agency that said a photocopy of the passport was sent to the bureau.” But an F.B.I. official told Bamford, “They refused to tell us because they didn’t want the F.B.I., they didn’t want John O’Neill in particular, muddying up their operation.” The 9/11 commission concluded, “None of this information—about Mihdhar’s U.S. visa or Hazmi’s travel to the United States—went to the FBI.”

Dale Watson says, however, that “no one in the agency—no one—would have intentionally withheld that from the F.B.I. I think it was an administrative screwup.”

One C.I.A. insider blames Cofer Black. “Cofer just sat on his ass and did nothing [when I pointed out a mistake he made on another matter], which was frankly consistent with how he did his work out at CTC, if you ask me.… Remember, he likes to say, ‘Oh, we did everything, but we didn’t have enough resources.’ Osama bin Laden is your No. 1 target. You know that two people with bin Laden’s group are meeting in Malaysia. And you do what? Handle it like it’s a routine matter … get around to it at some point. No urgency. No preparation or planning.”

Bamford quotes an F.B.I. official as saying, “I know someone who did lie, and said she brought documents down to the F.B.I., and you check the visitors logs and she had never got into the building.… Then she said she gave it to somebody else, she said ‘I may have faxed it down—I don’t remember.’”

MacGaffin is more forgiving. “There was a particular woman who is going to take to her grave the fact that she didn’t do this,” he says. “And she’s not a lazy woman. And the system didn’t expect her to do it. But she is responsible.… But you have to understand the environment she was in. Information was coming like a fire hose.”

On October 12, the same al-Qaeda operatives who had tried to bomb the U.S.S. The Sullivans loaded up another boat with explosives and drove it into the destroyer Cole, killing 17 crew members. Within a few weeks, Yemeni officials arrested two al-Qaeda operatives who had helped coordinate the attack. They indicated that the operation had been directed by a bin Laden operative named “Khallad.” An F.B.I. agent recognized the name and showed a photo of Khallad, provided by Yemeni authorities, to a key al-Qaeda informant in U.S. custody. He confirmed Khallad had been an intermediary between the Cole plotters and bin Laden. In January 2001—one year after al Mihdhar had vanished—the C.I.A. showed the informant two surveillance photographs of the Kuala Lumpur meeting. The informant was “90 percent” sure that one of the men in the photos was Khallad.

Again, it appears that the F.B.I. was kept in the dark. The 9/11 commission concludes: “[We] found that the CIA did not notify the FBI of this identification. DCI Tenet and Cofer Black testified before Congress’s Joint Inquiry into 9/11 that the FBI had access to this identification from the beginning. But drawing on an extensive record, including documents that were not available to the CIA personnel who drafted that testimony, we conclude this was not the case. The FBI’s primary Cole investigators had no knowledge that Khallad had been in Kuala Lumpur with Mihdhar and others until after the September 11 attacks. Because the FBI had not been informed in January 2000 about Mihdhar’s possession of a U.S. visa it had not then started looking for him in the United States. Because it did not know of the links between Khallad and Mihdhar it did not start looking for him in January 2001.”

“To me, that’s the one that’s toughest to get over,” admits Pat Damuro, head of the F.B.I.’s New York office. “If we would have known that earlier, we would have utilized surveillance, and, this is just hindsight as 20/20, maybe we would have found out something.”

When Clinton and Bush met at the White House on December 19 for two hours, to discuss the transition, Clinton couldn’t have been clearer about Islamic terrorism. “I think you will find that by far your biggest threat is bin Laden and the al-Qaeda,” he recalls saying. He told Bush that one of his major regrets as president was not getting bin Laden.

But Bush was not exactly a whiz on foreign policy. During the campaign, in response to reporters’ questions, he could not correctly identify either Pakistani leader General Pervez Musharraf or the Taliban. For that kind of knowledge, Bush depended on Condoleezza Rice, who had served as the N.S.C.’s director of Soviet and East European affairs in his father’s administration.

But Rice was a Sovietologist by training, and she was not up to speed on the Middle East. During the campaign, she suggested that Iran might be sending money and arms to the Taliban, when in fact the Taliban and Iran loathed each other, and Iran was supporting Massoud and the Northern Alliance in their attempt to overthrow the Taliban. When Richard Clarke briefed her on al-Qaeda for the first time, in January 2001, he got the impression she had never heard the term, Clarke recalled in his 2004 book, Against All Enemies. He warned Rice that al-Qaeda was not a few, isolated terrorists, but a major organization with cells in more than 50 countries, including the U.S. Outgoing national-security adviser Sandy Berger made a point of dropping in on the meeting, in order to underscore the gravity of the threat.

On January 25, Clarke followed up the briefing with a detailed memo to Rice, in which he begged, “We urgently need … a Principals level review on the al-Qaeda network.” Rice never responded directly to the memo, but instructed her deputy, Stephen Hadley, to look into it. What she did do next was effectively demote Clarke, removing him from the Cabinet-level principals’ meetings. Henceforth he would have to report to the principals through a second-tier deputies committee. The principals’ meeting on al-Qaeda Clarke was so urgently requesting did not occur until September 4.

But Rice wasn’t the only one in the new administration who didn’t get it. The president had assembled an administration with officials such as Dick Cheney and Donald Rumsfeld, who had been out of government since his father’s administration. They still mainly saw the world in terms of the Cold War model, in which the Communist nations were the enemy. Bush had little patience for the Clinton administration’s surgical approach to rooting out al-Qaeda. He told Rice he was “tired of swatting at flies” and wanted a broad, comprehensive plan for fighting terrorism, which would be framed within the context of Middle East policy. (When 9/11 commissioner Bob Kerrey asked Rice exactly what flies Bush had swatted, she fumbled embarrassingly for an answer.) Meanwhile, the new administration was spending its time and resources worrying about how to stop enemy missiles with an elaborate missile-defense shield, among other diversions, rather than how to stop a terrorist carrying a dirty bomb, a biological weapon, or a box cutter.

Those who had thought about the Middle East—such as former Defense Policy Advisory Board chairman Richard Perle, deputy assistant for national security for Cheney David Wurmser, Deputy Secretary of Defense Paul Wolfowitz, and Pentagon undersecretary of defense for policy Douglas Feith—were mostly neoconservatives. Many of them had ties to the right wing of Israeli politics, which opposed any negotiated settlement with the Palestinians. The neocons believed that Islamic terrorism should be addressed through regime change in Islamic countries hostile to Israel, and since the early 1990s they had been obsessed with getting rid of Saddam Hussein in Iraq. Once in power, they pressed that issue, despite the fact that there was little evidence Saddam was a sponsor of international terrorism. (The 9/11 Commission Report concluded that although there were “contacts” between Iraq and al-Qaeda, “we have seen no evidence that these [contacts] ever developed into a collaborative operational relationship.”)

After the deputies committee met on March 7, Clarke pointed out the flaws in framing the al-Qaeda problem as a long-range part of the administration’s comprehensive Middle East policy. He continued to stress that immediate action against the terror organization was imperative, but it had little effect. Frustrated with the administration’s approach, Clarke asked to be transferred to cyber security. In his book he wrote that his message to the new administration should have been clear: “You obviously do not think that terrorism is as important as I do since you are taking months to do anything; so get somebody else to do it who can be happy working at it at your pace.”

Meanwhile, Cofer Black and his CTC had decided that the solution to killing bin Laden was an armed Predator—a surveillance drone modified to carry a Hellfire missile. But the plan went nowhere because the Air Force cited technical problems, and Bush’s Cabinet was concerned about how it might affect overall policy in the region. According to Bamford, Alec Station’s Rich was still putting his chips on Massoud, whom he met with that spring in Paris, where he gave him another briefcase full of cash.

The Planes Operation was already far advanced. After January 15, 2000, when al Hazmi and al Mihdhar had arrived in Los Angeles from Bangkok, using valid tourist visas and their own passports, the two had settled in San Diego, where they eventually came to occupy Unit 127 of the Parkwood Apartments. With the help of a Yemeni acquaintance, Mohdar Abdullah, they obtained California driver’s licenses and applied to take English classes and courses at flight schools.

Parkwood Apartments manager Holly Ratchford remembers al Hazmi as polite and outgoing, though his English was limited. He would stop by the management office in the mornings and have coffee and cookies. Al Mihdhar was less outgoing. “I saw them watching and playing flight-simulator games when I was walking my dog at 10 or 11 at night. They would leave the front door open,” a neighbor told Time magazine. “Anytime you saw them, they were on their cell phones. What I found strange was that they always kept to themselves. Even if someone got in the pool, they got out.”

Sometimes the men would be picked up late at night by a limousine, yet they lived very simply, and the car they normally drove was a late-80s blue Toyota.

Al Hazmi’s and al Mihdhar’s lack of English seriously hindered their attempts to take flying lessons. They told an instructor at the Sorbi Flying Club who spoke Arabic that they wanted to learn to fly jets immediately; the instructor thought they were joking. He explained that they’d have to start with small planes and work their way up. Other instructors remember them focusing only on controlling the planes once in the air and not paying much attention to takeoffs or landings. By the end of May, they had given up learning to fly. (Al Hazmi and al Mihdhar would serve merely as “muscle” hijackers on 9/11; they would not pilot the planes.)

Al Mihdhar returned to Yemen in June and then traveled throughout the Middle East and Asia to recruit more of the 9/11 musclemen. Al Hazmi moved in with Abdussattar Shaikh, a respected member of the Al-Medina Al-Munawara mosque (which al Hazmi attended) and a retired professor of English at San Diego State University. In fact, Shaikh had known both al Hazmi and al Mihdhar, but he had no idea of their plans at the time. Al Hazmi and al Mihdhar also had no idea that Shaikh was an F.B.I. informant, whose job it was to report any suspicious activity in the Saudi community. (In his 2004 book, Intelligence Matters, Florida senator Bob Graham, a 10-year veteran of the Senate intelligence committee, relates how his staff discovered that al Hazmi had lived with Shaikh, and that the F.B.I. tried to cover it up. The F.B.I. refused to provide access to Shaikh, and questions asked on Graham’s behalf were never answered, under the pretext that the informant could be exposed—it didn’t matter that the informant’s identity had already been revealed in the press. Then the F.B.I. assigned a Justice Department lawyer to Shaikh. The agency insisted “vehemently” that the Senate not tell the American people that the hijackers had been in close contact with an F.B.I. informant. They removed or redacted any mention of the issue from the inquiry’s final report. While Graham at first believed the F.B.I. was not cooperating to avoid embarrassment, he later learned there was another reason. In November 2002, an F.B.I. source sent a letter to Graham explaining that the bureau received orders from the White House not to let congressional investigators interview the informant.)

Al Mihdhar was replaced in San Diego by Hani Hanjour, a Saudi who had visited the U.S. several times since 1991 and had earned his F.A.A. commercial-pilot certificate in 1999. (On 9/11 he would pilot American Airlines Flight 77 into the Pentagon.) He and al Hazmi traveled to Arizona, where Hanjour began training on a Boeing flight simulator.

Around the time that al Mihdhar left for Yemen, three hijackers from the Hamburg cell arrived on the East Coast. Jarrah flew to Venice, Florida, where he had already enrolled in a private-pilot program. Atta and al Shehhi soon made their way there, too, and by early July they were enrolled at Huffman Aviation, in Venice. They claimed they wanted to be commercial pilots in the U.A.E.; sometimes they told people that one was a Saudi prince and the other his bodyguard. Two staffers at the school called Atta “the little terrorist” behind his back. “He had hate oozing from him. You did not want to be in his presence,” one school official told the Chicago Sun-Times. “He tried to be intimidating, but he didn’t have the stature.” The owner of Huffman does not remember Atta fondly, either. “My personal feeling was Atta was an asshole, first-class,” he told Australian television, though he found al Shehhi to be “a very nice, likable person.” Atta and al Shehhi left the country during the holiday season, but returned in mid-January, despite the fact they did not have valid visas.

By the end of spring, Hanjour and al Hazmi were on the East Coast, awaiting the arrival of the other muscle hijackers. Clean-cut, polite, and keeping mainly to themselves, the new arrivals stayed in rented rooms or motels for weeks at a time. Most settled in Florida; some rented cars, opened post-office boxes and bank accounts. They joined local gyms to stay fit for the coming operation.

In the spring of 2001, says German journalist Oliver Schröm, 120 Israelis were investigated and deported from the United States. Accused of being spies posing as art students, they had been monitoring suspected Islamic terrorists. Schröm claims their exposure was an embarrassment to authorities, and both countries downplayed the incidents. Supposedly, one group of the Israelis had been living in close proximity to Atta and al Shehhi in Hollywood, Florida. Another group had been in Arizona, keeping tabs on Khalid al Mihdhar. According to Schröm, Israeli authorities warned the Americans several times about the terrorist groups inside the U.S., especially of al Mihdhar, but the warnings were not heeded. Nearly a month before the attacks, Schröm says, Israel gave U.S. intelligence a detailed report with the names of suspects they believed were preparing an attack on the U.S. Allegedly the report, too, was ignored. (An American intelligence official says, “I have nothing on [this story]. Ask Israeli intelligence.”)

By early summer, al Hazmi and Hanjour had traveled to Paterson, New Jersey, where they rented a one-room apartment. When the landlord came to inspect, he found six men living there. The other four were also hijackers.

Terrorist “chatter” picked up by N.S.A. and C.I.A. monitors had been spiking that summer, and the CTC started to notice that a number of well-known al-Qaeda operatives had gone underground. “We’re on the verge of more attacks that are larger and more deadly,” Cofer Black’s deputy warned a closed session of the House intelligence committee on June 4.

In June, an F.B.I. analyst—called Jane in The 9/11 Commission Report—assigned to the Cole investigation came across intelligence on the Kuala Lumpur meeting. When she went to New York on June 11 to meet with other F.B.I. agents working on the Cole case, Jane took along the surveillance photographs from Kuala Lumpur, as well as “Dave,” a C.I.A. analyst who had helped connect al Mihdhar to Khallad (and hence al-Qaeda). The New York agents were intrigued by the photos. Unfortunately, Jane and Dave each believed that government regulations prevented them from sharing the information about who was in the photos with the F.B.I. agents in New York. Had they done so, alarm bells would have gone off, and the F.B.I. could have started looking for Khalid al Mihdhar and Nawaf al Hazmi. Al Mihdhar had left the country in June 2000. No one noticed when he came back on July 4, 2001.

Analysts at Alec Station believed all the terrorist chatter might signal some kind of attack on July 4, but the holiday came and went quietly. Still, the chatter seemed to grow.

In the spring of 2001, a counterterrorism specialist in the bureau’s Phoenix office, named Kenneth Williams, began writing a memo to headquarters detailing his investigations of Middle Eastern flight students. He had become concerned about a group of Arab men attending Arizona flight schools. He had interviewed one, Zakaria Mustapha Soubra, and was deeply worried about what he had learned. Soubra had photographs of bin Laden tacked to the walls in his apartment and was driving a car registered to an Arab man who had been detained in 1999 for trying to enter the cockpit of a commercial airliner. Williams suspected Soubra might be involved in a plot to hijack or blow up planes.

In the memo, sent to headquarters on July 10, the F.B.I. man warned “of the possibility of a coordinated effort by USAMA BIN LADEN (UBL) to send students to attend civil aviation universities and colleges.” The memo named 10 people, including one the F.B.I. would later learn had been in contact with Hani Hanjour. He urged headquarters to consider preventive measures that included establishing ties with American flight schools and analyzing visa information of those attending them.

In Washington, Williams’s memo, one of hundreds that passed through headquarters each day, was sent to the F.B.I.’s Radical Fundamentalist and Osama bin Laden units. Senate investigators later interviewed F.B.I. supervisors who remembered reading it; they said it had provoked a discussion about whether the proposal was legal and whether investigating Arab flight-school students might be considered ethnic profiling. One analyst said she put the memo aside with a thought of studying it later.

Even today, F.B.I. officials dismiss the possibility that aggressively following up on the Williams memo would have had any effect on the 9/11 attacks.

“You can’t find the hijackers with the Phoenix memo—you can’t,” insists the F.B.I.’s Mike Rolince. “Maybe we could have detained someone who knew Hanjour. Maybe. But a judge [would’ve] kicked the crap out of us. If we wanted to look at all Arabs at schools in California, Arizona, and Florida? There are 1,625 flight schools, 82,000 flight instructors, and 69,000 ground instructors [in the country to interview]. There’s just no way that would have happened. No way.”

Tenet seemed truly to have been terrified that summer. He told the 9/11 commission that “the system was blinking red.” He had been briefing the president since spring about the frightening reports the agency had been getting in increasing numbers. Clarke told Vicky Ward for an article in the July issue of V.F. that “Tenet on 40 occasions in … morning meetings mentioned al-Qaeda to the president. Forty times, many of them in a very alarmed way, about a pending attack.”

On August 6, 2001, as President Bush was just beginning a monthlong summer vacation at his ranch, in Crawford, Texas, he was given a two-page Presidential Daily Briefing (P.D.B.) entitled “Bin Ladin Determined to Strike in US.” The P.D.B. outlined a brief history of bin Laden’s involvement in previous attacks and told of al-Qaeda sleeper cells in the U.S. Then it offered the conclusion that “FBI information … indicates patterns of suspicious activity in this country consistent with preparations for hijackings or other types of attacks, including recent surveillance of federal buildings in New York.” But, still, Bush was not concerned enough to interrupt his schedule of golf games. When the commissioners asked Rice about the P.D.B., she tried to avoid saying the title, but was forced to. Then she kept insisting it was “historical.” But two C.I.A. analysts who had helped prepare the P.D.B.—“Barbara S.” and “Dwayne D.”—told the 9/11 commission that the threat of bin Laden attacking inside the United States remained current and serious. And Clarke’s colleague William Wechsler told Ward that to call the P.D.B. historical was “absolutely ridiculous.… Intelligence reports to the president are very, very qualified, trying to be very accurate, trying to be very succinct.” Others have pointed out the obvious—the P.D.B.’s title is predictive, not historical.

On August 15, a flight instructor at the Pan Am International Flight Academy, in tiny Eagan, Minnesota, reported a suspicious new student—33-year-old Zacarias Moussaoui, who had arrived at the academy five days earlier and had quickly turned belligerent when asked about his background. Moussaoui, who had no evident piloting skills, wanted to learn to fly a 747. He said he didn’t intend to become a commercial pilot and was doing the training only as an “ego boosting thing.”

After being bounced around among various agents at the F.B.I.’s Minneapolis office, the instructor finally got the right person on the phone. “Do you realize how serious this is?” he asked. “A 747 fully loaded with fuel could be used as a weapon!”

That got the agent’s attention. The next day another F.B.I. agent and an I.N.S. agent confronted Moussaoui. He still refused to answer questions in any detail; in addition, he had $32,000 in a bank account, which he could not explain. The F.B.I. agent concluded that Moussaoui was an Islamic extremist who was planning to use his flight training for a terrorist operation. (Moussaoui, it turned out, was receiving money from Binalshibh, which tied him directly to al-Qaeda, but the F.B.I. would not discover this until after 9/11.)

Moussaoui was detained on immigration violations, but the Minneapolis F.B.I. could not persuade headquarters to let it treat him as a suspected terrorist, so his belongings, including a laptop, were not searched. This led to arguments between the Minneapolis office and supervisors in Washington, who believed Minneapolis was overreacting. A supervisor in Minneapolis replied that he was “trying to keep someone from taking a plane and crashing it into the World Trade Center.”

In late August, “Mary,” an F.B.I. analyst assigned to the C.I.A.’s Alec Station who had attended the June 11 meeting in New York, finally put the pieces of the al Mihdhar puzzle together and sounded the alarm. Once she realized that al Mihdhar had a U.S. visa, and that al Hazmi had entered the country on January 15, 2000, she contacted Jane at the F.B.I. Both agents got in touch with the I.N.S., which informed them that al Mihdhar had also entered the U.S. on January 15, 2000, and then again on July 4, 2001. The two men were added to the Tipoff watch list on August 24. Although it was too late, the F.B.I. now realized that al Mihdhar had to be found.

Jane sent a memo to the F.B.I. field office in New York. She called ahead to inform agents there that it was on its way, but the memo wouldn’t get there until August 28. She indicated that the New York office should start investigating as soon as possible, but the memo was labeled “routine,” which meant that the New York agents had up to 30 days to respond. The agent who received the memo forwarded it to his squad supervisor, who sent it along to investigators looking into the Cole bombing. As a result, one of the Cole investigators contacted Jane. But she refused to provide him with any more information because she apparently still did not understand the very complicated F.B.I. rules on information sharing (nor, it seems, did anyone else). The agent wrote her back: “Whatever has happened to this—someday someone will die.… The public will not understand why we were not more effective and throwing every resource we had at certain ‘problems.’ … The biggest threat to us now, UBL, is getting the most protection.”

After the memo arrived in New York, it was given to an agent as his very first assignment in counterterrorism. He began working on it several days later, checking databases for a criminal record and information from a driver’s license. On September 11, he forwarded Jane’s memo to Los Angeles, where al Mihdhar had first landed in the U.S.

In the days before 9/11, the hijackers left Florida and began to meet in and around their departure cities. On the morning of the hijackings, Atta and one of the muscle hijackers took a commuter flight from Portland, Maine, to Boston’s Logan Airport, where they met up with the other men about to hijack American Airlines Flight 11 and United Airlines Flight 175. Atta’s luggage did not make it onto the airplane he would crash into the north tower of the World Trade Center. When his luggage was later inspected, authorities found a copy of his will and a three-page document handwritten in Arabic. It contained instructions for the hijackers, a checklist for the mission, and prayers. It reminded the hijackers to remember their knives, IDs, and passports and to “check your weapons before departure.… Let every one of you sharpen his knife and kill his animal and bring about comfort and relief of his slaughter.”

“Be cheerful, happy, serene and comforted because you are doing a job which God loves,” Atta reminded the others. “Smile in the face of death, oh young man! For you are on your way to the everlasting paradise.”

When the first plane hit the World Trade Center, George Tenet was having breakfast at the St. Regis Hotel, in Washington, with his old friend and mentor David Boren, a former chairman of the Senate intelligence committee. As Bob Woodward reported, an aide interrupted, saying, “Mr. Director, there’s a serious problem.” He handed Tenet a phone. “So they put the plane into the building itself?” Tenet asked.

After telling Boren, “This has bin Laden all over it,” Tenet said, “I wonder if it has anything to do with this guy taking pilot training.”

Mike Scheuer was in his office when a friend called and told him to turn on the TV, which he did just in time to see the second plane hit. At that moment, he says, he felt “sadness more than anything else.… I was nearly physically sick that I had neither resigned in 1999 and told Congress what I knew nor resigned and published my book sooner.”

Richard Clarke was in the Ronald Reagan Building, three blocks from the White House, when he heard. He immediately drove to the White House and ran to Cheney’s office in the West Wing. They went with Condi Rice to the secure videoconferencing center, where he coordinated the White House response to the attacks.

James MacGaffin learned of the attacks, just after the first plane crashed into the World Trade Center, from the television in his office in Teddy Roosevelt’s old house in Washington. He had been working for months with the military and intelligence communities to develop new ways to penetrate al-Qaeda. “Despite broad understanding of the absolute seriousness of the al-Qaeda threat,” he says, “the old bureaucratic roadblocks to ‘new approaches’ still ruled. Are we really a match for foes like this? Or are we actually our own worst enemy?”

The really terrifying thing, says MacGaffin, now a president of AKE L.L.C., a Washington-based international security and consulting firm, is that “we still do not know significantly more about al-Qaeda in the United States than we did before 9/11. We have no penetrations of al-Qaeda in the United States now. We have some overseas, but not close enough to do the job. I’m a conservative Republican, but I’m so troubled by this stuff, it’s scary.”